1. Field of Invention
The present invention relates to a wearable muscular-force supplementing device to be worn at joints of the wrist, arm, knee, and the like of a user so as to generate supplementary muscular force.
2. Description of Related Art
Conventional wearable muscular-force supplementing devices are disclosed in, for example, Japanese Unexamined Patent Application Publication No. 7-163607 (hereinafter referred to as a xe2x80x9cfirst conventional artxe2x80x9d) and Japanese Unexamined Utility Model Application Publication No. 5-39518 (hereinafter referred to as a xe2x80x9csecond conventional artxe2x80x9d).
The first conventional art includes a thigh-worn portion to be worn on the thigh of a user, a shank-worn portion to be worn on the shank, power transmission arms fixed to the thigh-worn portion and the shank-worn portion at one end and connected to each other at the other end at a knee joint so as to bend and straighten the joint, a driving section using an electromotor for applying power for bending and straightening to the power transmission arms, and a power-source and control section for the electromotor and driving section. The power-source and control section is worn on the body of the user. In the driving section, a joint shaft connected to the power transmission arms rotates together with one of the power transmission arms. A gear mounted on an output shaft of the electromotor is meshed with a gear mounted on the joint shaft, and power transmission is enabled and disenabled between the gear of the joint shaft and the joint shaft via a clutch.
The first conventional art makes it possible to assist persons having low muscular strength in the legs, persons of advanced age, and the like in the climbing of stairs.
The second conventional art includes a shoulder-fixed member to be supported on the front side of the shoulder of a disabled arm, and an upper-arm-fixed member and a forearm-fixed member, respectively supported on the upper arm and the forearm. The upper-arm-fixed member and the forearm-fixed member are connected at the elbow, and an artificial rubber muscle is extended between the shoulder-fixed member and the forearm-fixed member so as to be expanded an contracted in response to changes in the internal air pressure thereof.
According to the second conventional art, a special electronic circuit (controller) and the like are unnecessary, and the range of movement can be easily set by utilizing the spring characteristics of the artificial rubber muscle in accordance with air pressure and contraction efficiency corresponding thereto.
However, the first conventional art has the following problems:
(1) While power transmission is enabled and disabled by the clutch, for example, when a user climbing the stairs, and the user is going to fall down while power is being transmitted, the clutch cannot be quickly disengaged. In this case, even if the user, who is going to fall down, desires to quickly assume a recovery attitude, the user cannot freely move the legs and may be placed into a dangerous situation because the clutch is engaged.
(2) Since supplementary muscular force is automatically generated in response to a specific attitude of the user, the user cannot do anything else except remove the device when supplementary muscular force is unnecessary.
(3) In order to change the power of the supplementary muscular force as the user desires, it is necessary to change the output of the electromotor in the driving section. For this reason, a high-output electromotor must be used to respond to increases and decreases in the power of supplementary muscular force. This increases the size of the device.
(4) A heavy power source must be worn on the body of the user, and this may limit the motion of the user. While a myoelectric sensor is used to check the muscular force of the user, mounting of the myoelectric sensor is troublesome, and inflammation of the skin is sometimes caused due to adhesive tape or the like used to hold the sensor on the skin.
(5) For example, when the device is worn on the body in winter, cold instruments are in contact with the skin, and the user feels cold and uncomfortable.
In contrast, the second conventional art also has the following problems:
(6) Even when the user, who is going to fall down, desires to quickly assume a recovery attitude, he or she cannot support the entirety of the body because the arm is restrained. This may lead to a dangerous situation.
(7) Since the artificial rubber muscle has only a single pressure chamber, when the pressure chamber is ruptured, supplementary muscular force is suddenly lost. In a case in which supplementary muscular force is suddenly lost while the user is carrying something heavy, the body of the user may be injured.
(8) Artificial rubber muscles may be arranged in parallel in order to increase the power of supplementary muscular force. When a plurality of artificial rubber muscles are thus arranged, the number of external tubes to be connected thereto is increased, and therefore, it is troublesome to handle the external tubes so that they do not become entangled.
(9) The artificial rubber muscle is stiffened and contracted by pressure, thereby bending the arm of the user. Since the contracted artificial rubber muscle lies in the bending direction of the arm of the user, however, it reduces the range of movement of the arm of the user.
(10) Since the artificial rubber muscle serving as an actuator is not in close contact with the body, problems occur; for example, a portion of clothing (a shirt or a coat) becomes entangled therein. Furthermore, when the user wears the device over a shirt, he or she cannot wear a jacket thereover.
(11) In a manner similar to that in the first conventional art, when the device is worn on the body in winter, the user feels cold and uncomfortable.
An object of the present invention is to provide a wearable muscular-force supplementing device which is easily handled with a fail-safe mechanism for the body of a user, for example, which immediately stops generation of supplementary muscular force in the case of an emergency and prevents generated force from being suddenly reduced even when an actuator breaks, which is easily wearable with the actuator not protruding from a joint of the user, which is so compact as not to reduce the range of movement of the joint of the user, which is so light in weight that it does not restrain the movement of the user, and which does not cause the user to feel uncomfortable, such as feel cold, when wearing the device.
A wearable muscular-force supplementing device according to an aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the controller has an artificial muscular-force releasing device that releases the joint from restraint by stopping generation of supplementary muscular force by the artificial muscular-force generator.
According to this invention, when the user assumes a dangerous attitude, for example, when the user is going to fall down, generation of supplementary muscular force in the artificial muscular-force generator is stopped, and therefore, the user can freely move the body without any restraint from the artificial muscular-force generator.
Preferably, the artificial muscular-force releasing device has a sensor that detects the attitude of the user, and a release controller that stops generation of supplementary muscular force by the artificial muscular-force generator when determining, based on information detected by the sensor, that the user is in a dangerous attitude, for example, indicating that the user is going to fall down.
In this case, the sensor detects a dangerous position, for example, a state in which the user is going to fall down. The release controller can stop generation of supplementary muscular force by the artificial muscular-force generator based on information detected by the sensor.
The controller may have a voice input device, and may control generation of supplementary muscular force to be applied to the joint by the artificial muscular-force generator or may exert control so as to operate the artificial muscular-force releasing device, based on voice input from the voice input device.
In this case, supplementary muscular force is generated in the artificial muscular-force generator when the user says xe2x80x9cStartxe2x80x9d, and the generation of supplementary muscular force by the artificial muscular-force generator is stopped when the user says xe2x80x9cStopxe2x80x9d. When the user says xe2x80x9cDangerxe2x80x9d, the artificial muscular-force releasing device is operated to release the joint from restraint.
The artificial muscular-force generator may have a fluid-pressure type actuator, and the controller may include a reservoir that stores fluid, a fluid feeding device that pressurizes and transfers the fluid received from the reservoir to the actuator, and a feeding-drive control device that controls the fluid feeding device. The artificial muscular-force releasing device may have a control valve interposed in a fluid path communicating with the actuator and connected to the reservoir while detouring around the fluid feeding device, and the release controller may have an opening control section that controls the opening of the control valve.
In this case, when the release controller detects, from an acceleration sensor, a dangerous attitude of the user, for example, a state in which the user is going to fall down, it exerts control so as to open the control valve. Thereby, the fluid in the actuator is fed back to the reservoir, and generation of supplementary muscular force by the artificial muscular-force generator can be stopped.
A wearable muscular-force supplementing device according to another aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the controller has a generated-force stabilizer that inhibits force generated by the artificial muscular-force generator from being reduced due to breakage.
In this case, even when an actuator breaks while the user is carrying something heavy, the generated-force stabilizer prevents force generated by the actuator from being suddenly reduced. Therefore, the body of the user will not be injured.
The artificial muscular-force generator may include a fluid-pressure type actuator having a plurality of pressure chambers, and the generated-force stabilizer may separate the pressure chambers.
In this case, even when the actuator is partly broken, since the generated-force stabilizer separates the broken pressure chamber, force generated by the actuator can be prevented from being suddenly reduced.
The controller may include a reservoir that stores fluid, a fluid feeding device that pressurizes and transfers the fluid received from the reservoir to the actuator, and a feeding-drive control device that controls the fluid feeding device. The generated-force stabilizer may include a pressure sensor that detects the pressures in the pressure chambers, control valves interposed in a plurality of flow paths connected between the fluid feeding device and the pressure chambers of the actuator, and a generated-force stabilization control section that closes a control valve connected to a given pressure chamber when it is determined based on information detected by the pressure sensor that the pressure in the pressure chamber has decreased.
In this case, the pressure sensor detects that a given pressure chamber of the actuator is in an abnormal condition. The generated-force stabilization control section closes a control valve connected to the given pressure chamber. Since the broken pressure chamber is thereby separated, the force generated by the actuator will not be suddenly reduced.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the artificial muscular-force generator is electrically driven, there are two power sources, a main power source and an auxiliary power source, the main power source and the auxiliary power source are connected to a power switching device, and the power switching device performs switching so as to supply power from the auxiliary power source for a predetermined time when power supply from the main power source is stopped.
In this case, since power is supplied from the auxiliary power source when supply from the main power source is stopped, it is possible to avoid the danger of a sudden stop of generation of supplementary muscular force.
The power switching device may have an alarm device for sounding an alarm when power supply from the auxiliary power source is started.
This makes it possible to reliably inform the user that power supply from the main power source has stopped.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the artificial muscular-force generator has a pair of mounting portions to be worn at two positions on the body of the user on both sides of the joint, and an actuator connected between the mounting portions, and the actuator has a restraint that prevents excessive supplementary muscular force from being applied to the joint of the user.
In this case, the joint will not be damaged by excessive supplementary muscular force. As the restraint, the mounting portions may be provided with stopper members placed opposed to each other so that the positions thereof are adjustable and so that the stopper members contact before excessive supplementary muscular force is applied to the joint of the user. As the restraint, a variable-length elastic belt may be connected between the mounting portions so that the force of the actuator is stopped by tension generated by the elastic belt before excessive supplementary muscular force is applied to the joint of the user.
This makes it possible to prevent, by a mechanical structure, the joint from bending excessively.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the artificial muscular-force generator has a pair of mounting portions to be worn at two positions on the body of the user on both sides of the joint, and an actuator connected between the mounting portions, the actuator includes a plurality of actuator divisions arranged in parallel and connected to one another between the mounting portions, the mounting portions have detachably connecting portions that detachably connect the actuator divisions thereto, and a predetermined number of actuator divisions are connected to the detachably connecting portions of the mounting portions in accordance with a desired power of supplementary muscular force.
In this case, since actuator force can be changed only by connecting a predetermined number of actuator divisions to the detachably connecting portions of the first and second mounting portions, it is possible to freely set the power of supplementary muscular force as the user desires. By detaching the actuator divisions connected to the detachably connecting portions of the first and second mounting portions, the artificial muscular-force generator can be made compact.
The actuator divisions may be formed of fluid-pressure type actuators each having a pressure chamber therein, and the detachably connecting portions of the mounting portions may also serve as fluid transfer connectors to transfer fluid serving as working fluid into and out of the pressure chambers of the actuator divisions.
In this case, the tubes and the like for supplying fluid are not exposed outside the device, and the artificial muscular-force generator can be handled easily.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the artificial muscular-force generator has an actuator serving as a fluid chamber having a pressure chamber, and the controller includes a fluid transfer control section that controls transfer of the fluid with respect to the actuator, and at least one of the actuator and the fluid transfer control section has a fluid discharge control section that discharges internal fluid to the outside.
In this case, when the fluid is a liquid, such as hydraulic oil, the weight of the device is reduced by discharging at least one of the fluid in the actuator and the fluid in the fluid transfer control section to the outside by the fluid discharge control section. This facilitates an operation of transporting the device in a non-operation state.
The fluid discharge control section may have a leakage alarm that detects leakage of the fluid and sounds an alarm when discharge of the fluid out of at least the actuator and the fluid transfer control section is stopped.
This makes it possible to allow the user to immediately ascertain that an abnormal condition exists in which fluid is leaking to the outside.
The controller may include a fluid supply control section capable of supplying the fluid from the outside to at least one of the actuator and the fluid transfer control section, and a filter placed at an inlet of the fluid supply control section so as to remove foreign matters mixed in the fluid. In this case, the filter removes impurities, such as dust, mixed in the fluid. For this reason, since the fluid transfer control section feeds and feeds back the fluid having no impurities, it is possible to substantially reduce problems resulting from impurities.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the controller is driven by power from an external power source, and has a power cord to be connected to the external power source, and a cord reel that winds up the power cord thereon.
In this case, when the power cord is drawn out of the cord reel only by a required length, it is prevented from becoming entangled.
The cord reel may be worn on the body of the user via a holder, and the holder may have a mechanism for allowing a cord-dispensing hole of the cord reel to freely point upward, downward, rightward, and leftward.
Since the cord-dispensing hole of the cord reel is thereby controlled so as to constantly point in the extending direction of the power cord (toward a socket), the power cord can be smoothly drawn out of the cord reel.
The controller may have a power cord alarm that sounds an alarm when it is determined that only a short length of power cord remains in the cord reel.
In this case, it is possible to avoid a dangerous operation, in which for example, the power cord is forcibly disconnected from a socket due to a great pulling force applied to a plug because only a short length of power cord remains in the cord reel.
A wearable muscular-force supplementing device according to a further aspect of the present invention includes an artificial muscular-force generator that applies supplementary muscular force for bending to a joint of a user, and a controller that controls the driving of the artificial muscular-force generator, wherein the artificial muscular-force generator has a flexible mounting portion shaped like a cylinder so as to wrap the joint of the user in close contact therewith, and a fluid-pressure type actuator formed integrally with the outer periphery of the mounting portion so as to apply supplementary muscular force to the joint while bending the mounting portion.
In this case, since no member protrudes from the mounting portion, the user can easily wear clothing with the device worn on the body.
The controller may have a heating device that heats fluid serving as working fluid for the actuator to a predetermined temperature.
In this case, when the fluid heated by the heating device flows into the actuator, the temperature of the mounting portion formed integrally with the actuator rises.
The mounting portion may be provided with a muscular force detector that measures muscular force based on pressing force temporarily applied to the skin of the user, and the controller may control supplementary muscular force generated by the actuator based on muscular force information obtained from the muscular force detector. The muscular force detector may include a driving motor, a transmission mechanism that transmits rotating force of the driving motor as linear motion to a pushrod, and a torque measuring instrument that measures the torque value of the driving motor when the skin is pushed by the pushrod and outputting the torque value as the pressing force to the controller.
Since this eliminates the necessity of placing the device into contact with the skin, as in a myoelectric sensor or the like, it is possible to reduce the time for measuring the muscular force and to prevent inflammation of the skin.
The actuator may include an inner actuator placed on the inner side of the joint, extending in the longitudinal direction of the outer periphery of the mounting portion, and having a pressure chamber made of an elastic material, and an outer actuator placed on the outer side of the joint, extending in the longitudinal direction of the outer periphery of the mounting portion, and having a pressure chamber made of an elastic material. The inner and outer actuators may each have a plurality of convex members fixed on the outer periphery of the mounting portion with a predetermined space therebetween in the longitudinal direction, and a plurality of elastic members placed in the spaces between the convex members. Each of the elastic members may be expanded and contracted in response to the inflow and outflow of fluid into and from the pressure chamber formed therein, and each of the convex members may be pressed by expansion of the elastic member so as to apply bending force to the mounting portion.
In this case, when the fluid flows into the pressure chambers of the elastic members of the inner actuator, bending force acts on the mounting portion and supplementary muscular force is applied so as to bend the joint of the user. When the fluid flows into the pressure chambers of the elastic members of the outer actuator, bending force to the mounting portion is released and supplementary muscular force can be applied so as to straighten the joint of the user.
The controller may exert control so as to transfer fluid between the pressure chambers of the elastic members constituting the inner actuator and the pressure chambers of the elastic members constituting the outer actuator.
In this case, the pressure chambers in the outer actuator also serve as reservoirs when putting fluid into the pressure chambers of the inner actuator, and the pressure chambers in the inner actuator also serve as reservoirs when putting fluid into the pressure chambers of the outer actuator. Therefore, no reservoirs are necessary, or only a reservoir having a small capacity is necessary so as to supplement leakage of a small amount of working fluid. This reduces the amount of working fluid and allows a smaller and lighter device.
The actuator may include an outer actuator placed on the outer side of the joint, extending in the longitudinal direction of the outer periphery of the mounting portion, and having a pressure chamber made of an elastic material, and the outer actuator may be expanded in the longitudinal direction in response to the inflow of the fluid into the pressure chamber so as to apply bending force to the mounting portion, and may be contracted in response to the outflow of the fluid from the pressure chamber so as to release the bending force on the mounting portion. The outer actuator may include a plurality of convex members fixed on the outer periphery of the mounting portion with a predetermined space therebetween in the longitudinal direction, and a plurality of elastic members placed in the spaces between the convex members. The elastic members may be expanded in the longitudinal direction in response to the inflow of the fluid in the pressure chamber formed therein so as to press the convex members and to apply bending force to the mounting portion.
In this case, when the outer actuator is expanded so as to apply bending force to the mounting portion, supplementary muscular force is applied to bend the joint of the user. When the outer actuator is contracted so as to release the bending force on the mounting portion, supplementary muscular force is applied to straighten the joint of the user. Since the outer actuator, which is hardened by pressure, is placed on the outer side of the joint, it does not hinder bending of the arm of the user and does not reduce the range of movement of the arm.
The controller may have a generated-force stabilizer that inhibits the force generated by the artificial muscular-force generator from being reduced due to breakage.
In this case, even when the artificial muscular-force generator breaks while the user is carrying something heavy, the generated-force stabilizer prevents the force generated by the artificial muscular-force generator from being suddenly reduced. Therefore, the body of the user will not be injured.
The convex members may function as stopper members for stopping application of supplementary muscular force by contacting with one another before excessive supplementary muscular force is applied to the joint of the user.
This makes it possible to prevent, by the mechanical structure, the joint from bending excessively.
Furthermore, the fluid may be liquid, and the outer periphery of the mounting portion may be coated with a periphery-coating member having a liquid absorbing function.